The present invention is directed to the field of waste management. More particularly, the present invention is directed to solid/liquid separation in both municipal and industrial applications especially for the field of waste management. The present invention is embodied in a de-watering container for transporting and reducing slurries, sludges, and waste streams, the container being made of a high molecular weight polyethylene (HMWPE).
Solid phase-liquid phase separation of materials is an important need in the environmental handling of slurries. This is often referred to simply as de-watering. There are a variety of settings where de-watering is required or desired. These include both municipal and industrial applications such as:                Environmental emergency response        Sewage treatment plants        Environmental disposal requirements that liquid be removed or reduced in landfills to meet federal and state regulations for disposal        De-watering fly ash at power plants        Reduction of waste volume from sources like                    Paper mills            Chemical factories            Textile mills            Pharmaceutical operations            Food processing            Mining industries and others                        Removal of solids from storm water runoff        De-watering lagoon sludge        De-watering grease and grit from retail food effluent streams        De-watering clarifier ponds at wastewater and water treatment in sludge and septic handling        Recover the material as a product        Cleaning drilling mud for reuse in the gas well drilling process, or        Other needs such as to clarify the aqueous portion of the mixture.        
Currently, solid-liquid phase separation is completed by a variety of means including: centrifuges, settling ponds, belt presses, filter presses and de-watering filter containers. All share the objective to reduce sludge to a fraction of original volume, shrinking the handling and disposal costs and returning water or the carrying liquid to a reusable status. Existing de-watering containers usually use gravity or vacuum in concert with a flocculent additive to help coagulate and congeal the separation of solid-liquid phases contained within.
The present invention is directed to a new style of de-watering filter container: an all poly de-watering container. Currently, de-watering containers are made of carbon steel and coated or painted with coatings to protect the steel from corrosion against the corrosive solid-liquid slurries they are exposed to. The coatings, as good as they are, break down or are damaged in handling, causing the containers to corrode/rust so that the containers must be discarded or refurbished to continue to perform satisfactorily. De-watering containers often have a sub base that fits a roll-off truck application for handling and disposing of the de-watered, solid product. De-watering containers are sealed, liquid tight by design. Patent numbers of current steel based products include 4,871,454 and 5,595,654.
The poly dewatering container of the present invention is unique in that it has:    1. an interior of all poly components of container vessel floor and walls which are corrosion-resistant to septic sludges;    2. the partition support for the filter panels is also poly, not steel nor other metal;    3. the filter media is non metal and/or non-corrosive plastic as well; and,    4. the piping fittings through the walls into and out of the container are also poly.
The entire solid-liquid exposed portion of the container is unique in that it is non-corrosive poly. This poly is high molecular weight polyethylene (HMWPE) that is extrusion welded to have a water tight seal. It includes a rubber gasketed tailgate on the gated option design to seal the sludge being de-watered internally. The fasteners inside are non-corrosive stainless steel or poly.
Other features include:                All internal components of the poly de-watering container are plastic and non-metal (except for stainless steel fasteners).        This is a non-porous, non-corrosive resistant containment.        The unit has an operating temperature range from about −30 degrees Fahrenheit (if the liquid can be workable at that temperature) to about +160 degrees Fahrenheit.        The poly for the container walls is a special (HMWPE) recipe for added slipperiness, non-adherence and shedding of material contents.                    This slipperiness cleans out several times faster than conventional carbon steel containers with less build-up on the exposed walls.            This slipperiness resists the build-up of hard water deposits which is common in conventional steel and metal piping.                        Will not rust and wear when introduced to the same de-watering material contents that corrode carbon steel containers. This also eliminates the need to rebuild or refurbish rusted out carbon steel containers.        The poly container does not require the harsh, caustic surface preparation of steel containers for paint.        The poly container does not require the harsh, environmentally unfriendly coatings such as galvanizing, epoxy or urethanes on steel.        The Poly sheet for the container construction can be thermo-formed and extrusion welded without losing any of the poly strength or release properties.        The Poly de-watering container is designed with adequate reinforcement for the rigors of industrial-commercial-municipal use in dewatering.        The Poly de-watering container is designed to be used on available transportation systems such as roll-off units or as custom built transport units.        The Poly de-watering container does not have the issue of dissimilar metals reaction, anodic or cathodic conductivity corrosion that containers using different metals exhibit.        The Poly de-watering container uses typical industrial, sealed sliding hinges and latches on its gates and latches to seal liquid tight.        The Poly de-watering container is lighter than similar sized conventional units providing more useable hauling payload.        The Poly de-watering container uses poly for the partition and space component behind the filter cloth. This includes poly materials such as poly grating or poly cuspated plastic.Various other features, advantages, and characteristics of the present invention will become apparent after a reading of the following detailed description.        